The latest version of Samsung's Galaxy S smartphones features biometric security, the electronics giant has announced.

The Galaxy S5, unveiled at the Mobile World Congress in Barcelona, Spain, includes a fingerprint scanner to unlock the device.

The mobile is also water and dust resistant, and features a 16-megapixel camera which Samsung claims has the world's fastest autofocus speed of 0.3 seconds. The S5 will be available to buy from April.

Simon Stanford, vice president for the IT and mobile division of Samsung in the UK and Ireland, said: " We've decided to go back to basics with the Galaxy S5 and focus on the features and things that matter the most to our customers - namely the camera, ability to view and download data and content quickly and their health and well-being.

"People want a smartphone that enhances and enables their mobile life. The Galaxy S5 represents just that, and we're excited to see the response to our latest flagship smartphone device."

Meanwhile, mobile technology giants Sony and Nokia renewed the battle over the smartphone market, also announcing new devices at the event.

Japanese handset maker Sony unveiled its Xperia Z2 smartphone and tablet range, which will introduce 4K high-resolution video technology to the mobile market for the first time. The Z2's 20.7 megapixel camera will offer four times the detail of a HD camera and will be the world's first waterproof smartphone and tablet, according to the company.

The new device will also feature digital noise cancelling technology and is the slimmest and lightest phone and tablet, say Sony. The Z2 will go on global sale next month.

"With Xperia Z2 we have taken our premium Z series to the next level, delivering unique experiences that only Sony can offer," said Kunimasa Suzuki, president and chief executive, Sony Mobile Communications.

"We have redefined the smartphone once again through our camera. Xperia Z2 offers an innovative experience that captures memories in stunning detail through 4K video shooting, or offers new ways to use the camera with our unique Xperia camera apps."

Sony also announced details of its mid-range Xperia M2 smartphone, featuring waterproof technology and powered by Android. The M2 will go on global release from April 2014.

The new devices emphasise Sony's commitment to hardware improvements as the company aims to consolidate its position behind Apple and Samsung in the smartphone market.

Finnish company Nokia also announced the release of its first ever Android smartphones aimed at consumers in emerging markets.

The Nokia X, X+ and XL will use Google's Android operating system, as seen in Sony devices, rather than Microsoft's Windows Phone technology featured in Nokia's Lumia range.

However, the low-cost Nokia X devices will not feature many of the Google services that come with Android, and instead emphasise Microsoft services such as Bing, Skype and Outlook.The X range will also feature the resizeable home-screen tiles, resembling those on Windows Phone.

Microsoft is buying Nokia's phone business and patent rights in a 5.4 billion euro (£4.5 billion) deal expected to be completed next month.